Canning tomatoes is quite easy and you can use this method for other fruits and vegetables that have been processed for 15 minutes or longer.
Heat jars and lids in simmering water until they are ready for use.
Ladle hot tomato sauce into jars leaving 1/4” of head space or room at the top.
Remove any air bubbles.
Wipe rim
Center hold lid on jar and apply band so finger tight
Process in boiling water for 10 min. Let cool.
I put mine in the oven for 10 min at 225 degrees.
Lid should have a tight seal when cool.
Do not reuse lids.